Actual source code: hmg.c
1: #include <petscdm.h>
2: #include <petsc/private/hashmapi.h>
3: #include <petsc/private/matimpl.h>
4: #include <petsc/private/pcmgimpl.h>
5: #include <petsc/private/pcimpl.h>
7: typedef struct {
8: PC innerpc; /* A MG inner PC (Hypre or PCGAMG) to setup interpolations and coarse operators */
9: char *innerpctype; /* PCGAMG or PCHYPRE */
10: PetscBool reuseinterp; /* A flag indicates if or not to reuse the interpolations */
11: PetscBool subcoarsening; /* If or not to use a subspace-based coarsening algorithm */
12: PetscBool usematmaij; /* If or not to use MatMAIJ for saving memory */
13: PetscInt component; /* Which subspace is used for the subspace-based coarsening algorithm? */
14: } PC_HMG;
16: static PetscErrorCode PCHMGExtractSubMatrix_Private(Mat pmat, Mat *submat, MatReuse reuse, PetscInt component, PetscInt blocksize)
17: {
18: IS isrow;
19: PetscInt rstart, rend;
20: MPI_Comm comm;
22: PetscFunctionBegin;
23: PetscCall(PetscObjectGetComm((PetscObject)pmat, &comm));
24: PetscCheck(component < blocksize, comm, PETSC_ERR_ARG_INCOMP, "Component %" PetscInt_FMT " should be less than block size %" PetscInt_FMT " ", component, blocksize);
25: PetscCall(MatGetOwnershipRange(pmat, &rstart, &rend));
26: PetscCheck((rend - rstart) % blocksize == 0, comm, PETSC_ERR_ARG_INCOMP, "Block size %" PetscInt_FMT " is inconsistent for [%" PetscInt_FMT ", %" PetscInt_FMT ") ", blocksize, rstart, rend);
27: PetscCall(ISCreateStride(comm, (rend - rstart) / blocksize, rstart + component, blocksize, &isrow));
28: PetscCall(MatCreateSubMatrix(pmat, isrow, isrow, reuse, submat));
29: PetscCall(ISDestroy(&isrow));
30: PetscFunctionReturn(PETSC_SUCCESS);
31: }
33: static PetscErrorCode PCHMGExpandInterpolation_Private(Mat subinterp, Mat *interp, PetscInt blocksize)
34: {
35: PetscInt subrstart, subrend, subrowsize, subcolsize, subcstart, subcend, rowsize, colsize;
36: PetscInt subrow, row, nz, *d_nnz, *o_nnz, i, j, dnz, onz, max_nz, *indices;
37: const PetscInt *idx;
38: const PetscScalar *values;
39: MPI_Comm comm;
41: PetscFunctionBegin;
42: PetscCall(PetscObjectGetComm((PetscObject)subinterp, &comm));
43: PetscCall(MatGetOwnershipRange(subinterp, &subrstart, &subrend));
44: subrowsize = subrend - subrstart;
45: rowsize = subrowsize * blocksize;
46: PetscCall(PetscCalloc2(rowsize, &d_nnz, rowsize, &o_nnz));
47: PetscCall(MatGetOwnershipRangeColumn(subinterp, &subcstart, &subcend));
48: subcolsize = subcend - subcstart;
49: colsize = subcolsize * blocksize;
50: max_nz = 0;
51: for (subrow = subrstart; subrow < subrend; subrow++) {
52: PetscCall(MatGetRow(subinterp, subrow, &nz, &idx, NULL));
53: if (max_nz < nz) max_nz = nz;
54: dnz = 0;
55: onz = 0;
56: for (i = 0; i < nz; i++) {
57: if (idx[i] >= subcstart && idx[i] < subcend) dnz++;
58: else onz++;
59: }
60: for (i = 0; i < blocksize; i++) {
61: d_nnz[(subrow - subrstart) * blocksize + i] = dnz;
62: o_nnz[(subrow - subrstart) * blocksize + i] = onz;
63: }
64: PetscCall(MatRestoreRow(subinterp, subrow, &nz, &idx, NULL));
65: }
66: PetscCall(MatCreateAIJ(comm, rowsize, colsize, PETSC_DETERMINE, PETSC_DETERMINE, 0, d_nnz, 0, o_nnz, interp));
67: PetscCall(MatSetOption(*interp, MAT_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
68: PetscCall(MatSetOption(*interp, MAT_IGNORE_ZERO_ENTRIES, PETSC_TRUE));
69: PetscCall(MatSetOption(*interp, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE));
70: PetscCall(MatSetFromOptions(*interp));
72: PetscCall(MatSetUp(*interp));
73: PetscCall(PetscFree2(d_nnz, o_nnz));
74: PetscCall(PetscMalloc1(max_nz, &indices));
75: for (subrow = subrstart; subrow < subrend; subrow++) {
76: PetscCall(MatGetRow(subinterp, subrow, &nz, &idx, &values));
77: for (i = 0; i < blocksize; i++) {
78: row = subrow * blocksize + i;
79: for (j = 0; j < nz; j++) indices[j] = idx[j] * blocksize + i;
80: PetscCall(MatSetValues(*interp, 1, &row, nz, indices, values, INSERT_VALUES));
81: }
82: PetscCall(MatRestoreRow(subinterp, subrow, &nz, &idx, &values));
83: }
84: PetscCall(PetscFree(indices));
85: PetscCall(MatAssemblyBegin(*interp, MAT_FINAL_ASSEMBLY));
86: PetscCall(MatAssemblyEnd(*interp, MAT_FINAL_ASSEMBLY));
87: PetscFunctionReturn(PETSC_SUCCESS);
88: }
90: static PetscErrorCode PCSetUp_HMG(PC pc)
91: {
92: Mat PA, submat;
93: PC_MG *mg = (PC_MG *)pc->data;
94: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
95: MPI_Comm comm;
96: PetscInt level;
97: PetscInt num_levels;
98: Mat *operators, *interpolations;
99: PetscInt blocksize;
100: const char *prefix;
101: PCMGGalerkinType galerkin;
103: PetscFunctionBegin;
104: PetscCall(PetscObjectGetComm((PetscObject)pc, &comm));
105: if (pc->setupcalled) {
106: if (hmg->reuseinterp) {
107: /* If we did not use Galerkin in the last call or we have a different sparsity pattern now,
108: * we have to build from scratch
109: * */
110: PetscCall(PCMGGetGalerkin(pc, &galerkin));
111: if (galerkin == PC_MG_GALERKIN_NONE || pc->flag != SAME_NONZERO_PATTERN) pc->setupcalled = PETSC_FALSE;
112: PetscCall(PCMGSetGalerkin(pc, PC_MG_GALERKIN_PMAT));
113: PetscCall(PCSetUp_MG(pc));
114: PetscFunctionReturn(PETSC_SUCCESS);
115: } else {
116: PetscCall(PCReset_MG(pc));
117: pc->setupcalled = PETSC_FALSE;
118: }
119: }
121: /* Create an inner PC (GAMG or HYPRE) */
122: if (!hmg->innerpc) {
123: PetscCall(PCCreate(comm, &hmg->innerpc));
124: /* If users do not set an inner pc type, we need to set a default value */
125: if (!hmg->innerpctype) {
126: /* If hypre is available, use hypre, otherwise, use gamg */
127: #if PetscDefined(HAVE_HYPRE)
128: PetscCall(PetscStrallocpy(PCHYPRE, &hmg->innerpctype));
129: #else
130: PetscCall(PetscStrallocpy(PCGAMG, &hmg->innerpctype));
131: #endif
132: }
133: PetscCall(PCSetType(hmg->innerpc, hmg->innerpctype));
134: }
135: PetscCall(PCGetOperators(pc, NULL, &PA));
136: /* Users need to correctly set a block size of matrix in order to use subspace coarsening */
137: PetscCall(MatGetBlockSize(PA, &blocksize));
138: if (blocksize <= 1) hmg->subcoarsening = PETSC_FALSE;
139: /* Extract a submatrix for constructing subinterpolations */
140: if (hmg->subcoarsening) {
141: PetscCall(PCHMGExtractSubMatrix_Private(PA, &submat, MAT_INITIAL_MATRIX, hmg->component, blocksize));
142: PA = submat;
143: }
144: PetscCall(PCSetOperators(hmg->innerpc, PA, PA));
145: if (hmg->subcoarsening) PetscCall(MatDestroy(&PA));
146: /* Setup inner PC correctly. During this step, matrix will be coarsened */
147: PetscCall(PCSetUseAmat(hmg->innerpc, PETSC_FALSE));
148: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)pc, &prefix));
149: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)hmg->innerpc, prefix));
150: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)hmg->innerpc, "hmg_inner_"));
151: PetscCall(PCSetFromOptions(hmg->innerpc));
152: PetscCall(PCSetUp(hmg->innerpc));
154: /* Obtain interpolations IN PLACE. For BoomerAMG, (I,J,data) is reused to avoid memory overhead */
155: PetscCall(PCGetInterpolations(hmg->innerpc, &num_levels, &interpolations));
156: /* We can reuse the coarse operators when we do the full space coarsening */
157: if (!hmg->subcoarsening) PetscCall(PCGetCoarseOperators(hmg->innerpc, &num_levels, &operators));
159: PetscCall(PCDestroy(&hmg->innerpc));
160: hmg->innerpc = NULL;
161: PetscCall(PCMGSetLevels_MG(pc, num_levels, NULL));
162: /* Set coarse matrices and interpolations to PCMG */
163: for (level = num_levels - 1; level > 0; level--) {
164: Mat P = NULL, pmat = NULL;
165: Vec b, x, r;
166: if (hmg->subcoarsening) {
167: if (hmg->usematmaij) {
168: PetscCall(MatCreateMAIJ(interpolations[level - 1], blocksize, &P));
169: PetscCall(MatDestroy(&interpolations[level - 1]));
170: } else {
171: /* Grow interpolation. In the future, we should use MAIJ */
172: PetscCall(PCHMGExpandInterpolation_Private(interpolations[level - 1], &P, blocksize));
173: PetscCall(MatDestroy(&interpolations[level - 1]));
174: }
175: } else {
176: P = interpolations[level - 1];
177: }
178: PetscCall(MatCreateVecs(P, &b, &r));
179: PetscCall(PCMGSetInterpolation(pc, level, P));
180: PetscCall(PCMGSetRestriction(pc, level, P));
181: PetscCall(MatDestroy(&P));
182: /* We reuse the matrices when we do not do subspace coarsening */
183: if ((level - 1) >= 0 && !hmg->subcoarsening) {
184: pmat = operators[level - 1];
185: PetscCall(PCMGSetOperators(pc, level - 1, pmat, pmat));
186: PetscCall(MatDestroy(&pmat));
187: }
188: PetscCall(PCMGSetRhs(pc, level - 1, b));
190: PetscCall(PCMGSetR(pc, level, r));
191: PetscCall(VecDestroy(&r));
193: PetscCall(VecDuplicate(b, &x));
194: PetscCall(PCMGSetX(pc, level - 1, x));
195: PetscCall(VecDestroy(&x));
196: PetscCall(VecDestroy(&b));
197: }
198: PetscCall(PetscFree(interpolations));
199: if (!hmg->subcoarsening) PetscCall(PetscFree(operators));
200: /* Turn Galerkin off when we already have coarse operators */
201: PetscCall(PCMGSetGalerkin(pc, hmg->subcoarsening ? PC_MG_GALERKIN_PMAT : PC_MG_GALERKIN_NONE));
202: PetscCall(PCSetDM(pc, NULL));
203: PetscCall(PCSetUseAmat(pc, PETSC_FALSE));
204: PetscObjectOptionsBegin((PetscObject)pc);
205: PetscCall(PCSetFromOptions_MG(pc, PetscOptionsObject)); /* should be called in PCSetFromOptions_HMG(), but cannot be called prior to PCMGSetLevels() */
206: PetscOptionsEnd();
207: PetscCall(PCSetUp_MG(pc));
208: PetscFunctionReturn(PETSC_SUCCESS);
209: }
211: static PetscErrorCode PCDestroy_HMG(PC pc)
212: {
213: PC_MG *mg = (PC_MG *)pc->data;
214: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
216: PetscFunctionBegin;
217: PetscCall(PCDestroy(&hmg->innerpc));
218: PetscCall(PetscFree(hmg->innerpctype));
219: PetscCall(PetscFree(hmg));
220: PetscCall(PCDestroy_MG(pc));
222: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetReuseInterpolation_C", NULL));
223: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetUseSubspaceCoarsening_C", NULL));
224: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetInnerPCType_C", NULL));
225: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetCoarseningComponent_C", NULL));
226: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGUseMatMAIJ_C", NULL));
227: PetscFunctionReturn(PETSC_SUCCESS);
228: }
230: static PetscErrorCode PCView_HMG(PC pc, PetscViewer viewer)
231: {
232: PC_MG *mg = (PC_MG *)pc->data;
233: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
234: PetscBool isascii;
236: PetscFunctionBegin;
237: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
238: if (isascii) {
239: PetscCall(PetscViewerASCIIPrintf(viewer, " Reuse interpolation: %s\n", hmg->reuseinterp ? "true" : "false"));
240: PetscCall(PetscViewerASCIIPrintf(viewer, " Use subspace coarsening: %s\n", hmg->subcoarsening ? "true" : "false"));
241: PetscCall(PetscViewerASCIIPrintf(viewer, " Coarsening component: %" PetscInt_FMT " \n", hmg->component));
242: PetscCall(PetscViewerASCIIPrintf(viewer, " Use MatMAIJ: %s \n", hmg->usematmaij ? "true" : "false"));
243: PetscCall(PetscViewerASCIIPrintf(viewer, " Inner PC type: %s \n", hmg->innerpctype));
244: }
245: PetscCall(PCView_MG(pc, viewer));
246: PetscFunctionReturn(PETSC_SUCCESS);
247: }
249: static PetscErrorCode PCSetFromOptions_HMG(PC pc, PetscOptionItems PetscOptionsObject)
250: {
251: PC_MG *mg = (PC_MG *)pc->data;
252: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
254: PetscFunctionBegin;
255: PetscOptionsHeadBegin(PetscOptionsObject, "HMG");
256: PetscCall(PetscOptionsBool("-pc_hmg_reuse_interpolation", "Reuse the interpolation operators when possible (cheaper, weaker when matrix entries change a lot)", "PCHMGSetReuseInterpolation", hmg->reuseinterp, &hmg->reuseinterp, NULL));
257: PetscCall(PetscOptionsBool("-pc_hmg_use_subspace_coarsening", "Use the subspace coarsening to compute the interpolations", "PCHMGSetUseSubspaceCoarsening", hmg->subcoarsening, &hmg->subcoarsening, NULL));
258: PetscCall(PetscOptionsBool("-pc_hmg_use_matmaij", "Use MatMAIJ store interpolation for saving memory", "PCHMGSetInnerPCType", hmg->usematmaij, &hmg->usematmaij, NULL));
259: PetscCall(PetscOptionsInt("-pc_hmg_coarsening_component", "Which component is chosen for the subspace-based coarsening algorithm", "PCHMGSetCoarseningComponent", hmg->component, &hmg->component, NULL));
260: PetscOptionsHeadEnd();
261: PetscFunctionReturn(PETSC_SUCCESS);
262: }
264: static PetscErrorCode PCHMGSetReuseInterpolation_HMG(PC pc, PetscBool reuse)
265: {
266: PC_MG *mg = (PC_MG *)pc->data;
267: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
269: PetscFunctionBegin;
270: hmg->reuseinterp = reuse;
271: PetscFunctionReturn(PETSC_SUCCESS);
272: }
274: /*@
275: PCHMGSetReuseInterpolation - Reuse the interpolation matrices in `PCHMG` after changing the matrices numerical values
277: Logically Collective
279: Input Parameters:
280: + pc - the `PCHMG` context
281: - reuse - `PETSC_TRUE` indicates that `PCHMG` will reuse the interpolations
283: Options Database Key:
284: . -pc_hmg_reuse_interpolation <true | false> - Whether or not to reuse the interpolations. If true, it potentially save the compute time.
286: Level: beginner
288: Note:
289: This decreases the set up time of the `PC` significantly but may slow the convergence of the iterative method, `KSP`, that is using the `PCHMG`
291: .seealso: [](ch_ksp), `PCHMG`, `PCGAMG`, `PCHMGSetUseSubspaceCoarsening()`, `PCHMGSetCoarseningComponent()`, `PCHMGSetInnerPCType()`
292: @*/
293: PetscErrorCode PCHMGSetReuseInterpolation(PC pc, PetscBool reuse)
294: {
295: PetscFunctionBegin;
297: PetscUseMethod(pc, "PCHMGSetReuseInterpolation_C", (PC, PetscBool), (pc, reuse));
298: PetscFunctionReturn(PETSC_SUCCESS);
299: }
301: static PetscErrorCode PCHMGSetUseSubspaceCoarsening_HMG(PC pc, PetscBool subspace)
302: {
303: PC_MG *mg = (PC_MG *)pc->data;
304: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
306: PetscFunctionBegin;
307: hmg->subcoarsening = subspace;
308: PetscFunctionReturn(PETSC_SUCCESS);
309: }
311: /*@
312: PCHMGSetUseSubspaceCoarsening - Use subspace coarsening in `PCHMG`
314: Logically Collective
316: Input Parameters:
317: + pc - the `PCHMG` context
318: - subspace - `PETSC_TRUE` indicates that `PCHMG` will use the subspace coarsening
320: Options Database Key:
321: . -pc_hmg_use_subspace_coarsening <true | false> - Whether or not to use subspace coarsening (that is, coarsen a submatrix).
323: Level: beginner
325: .seealso: [](ch_ksp), `PCHMG`, `PCHMGSetReuseInterpolation()`, `PCHMGSetCoarseningComponent()`, `PCHMGSetInnerPCType()`
326: @*/
327: PetscErrorCode PCHMGSetUseSubspaceCoarsening(PC pc, PetscBool subspace)
328: {
329: PetscFunctionBegin;
331: PetscUseMethod(pc, "PCHMGSetUseSubspaceCoarsening_C", (PC, PetscBool), (pc, subspace));
332: PetscFunctionReturn(PETSC_SUCCESS);
333: }
335: static PetscErrorCode PCHMGSetInnerPCType_HMG(PC pc, PCType type)
336: {
337: PC_MG *mg = (PC_MG *)pc->data;
338: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
340: PetscFunctionBegin;
341: PetscCall(PetscStrallocpy(type, &hmg->innerpctype));
342: PetscFunctionReturn(PETSC_SUCCESS);
343: }
345: /*@
346: PCHMGSetInnerPCType - Set an inner `PC` type to be used in the `PCHMG` preconditioner. That is the method used to compute
347: the hierarchy of restriction operators.
349: Logically Collective
351: Input Parameters:
352: + pc - the `PCHMG` context
353: - type - `PCHYPRE` or `PCGAMG` coarsening algorithm
355: Options Database Key:
356: . -hmg_inner_pc_type <hypre, gamg> - What method is used to coarsen matrix
358: Level: beginner
360: .seealso: [](ch_ksp), `PCHMG`, `PCType`, `PCHMGSetReuseInterpolation()`, `PCHMGSetUseSubspaceCoarsening()`, `PCHMGSetCoarseningComponent()`
361: @*/
362: PetscErrorCode PCHMGSetInnerPCType(PC pc, PCType type)
363: {
364: PetscFunctionBegin;
366: PetscUseMethod(pc, "PCHMGSetInnerPCType_C", (PC, PCType), (pc, type));
367: PetscFunctionReturn(PETSC_SUCCESS);
368: }
370: static PetscErrorCode PCHMGSetCoarseningComponent_HMG(PC pc, PetscInt component)
371: {
372: PC_MG *mg = (PC_MG *)pc->data;
373: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
375: PetscFunctionBegin;
376: hmg->component = component;
377: PetscFunctionReturn(PETSC_SUCCESS);
378: }
380: /*@
381: PCHMGSetCoarseningComponent - Set which component of the PDE is used for the subspace-based coarsening algorithm in the preconditioner `PCHMG`
383: Logically Collective
385: Input Parameters:
386: + pc - the `PCHMG` context
387: - component - which component `PC` will coarsen
389: Options Database Key:
390: . -pc_hmg_coarsening_component <i> - Which component is chosen for the subspace-based coarsening algorithm
392: Level: beginner
394: Note:
395: By default it uses the first component
397: .seealso: [](ch_ksp), `PCHMG`, `PCType`, `PCGAMG`, `PCHMGSetReuseInterpolation()`, `PCHMGSetUseSubspaceCoarsening()`, `PCHMGSetInnerPCType()`
398: @*/
399: PetscErrorCode PCHMGSetCoarseningComponent(PC pc, PetscInt component)
400: {
401: PetscFunctionBegin;
403: PetscUseMethod(pc, "PCHMGSetCoarseningComponent_C", (PC, PetscInt), (pc, component));
404: PetscFunctionReturn(PETSC_SUCCESS);
405: }
407: static PetscErrorCode PCHMGUseMatMAIJ_HMG(PC pc, PetscBool usematmaij)
408: {
409: PC_MG *mg = (PC_MG *)pc->data;
410: PC_HMG *hmg = (PC_HMG *)mg->innerctx;
412: PetscFunctionBegin;
413: hmg->usematmaij = usematmaij;
414: PetscFunctionReturn(PETSC_SUCCESS);
415: }
417: /*@
418: PCHMGUseMatMAIJ - Set a flag that indicates if or not to use `MATMAIJ` for the interpolation matrices to save memory
420: Logically Collective
422: Input Parameters:
423: + pc - the `PCHMG` context
424: - usematmaij - `PETSC_TRUE` (default) to use `MATMAIJ` for interpolations.
426: Options Database Key:
427: . -pc_hmg_use_matmaij - <true | false >
429: Level: beginner
431: .seealso: [](ch_ksp), `PCHMG`, `PCType`, `PCGAMG`
432: @*/
433: PetscErrorCode PCHMGUseMatMAIJ(PC pc, PetscBool usematmaij)
434: {
435: PetscFunctionBegin;
437: PetscUseMethod(pc, "PCHMGUseMatMAIJ_C", (PC, PetscBool), (pc, usematmaij));
438: PetscFunctionReturn(PETSC_SUCCESS);
439: }
441: /*MC
442: PCHMG - Preconditioner for multiple component PDE problems that constructs a hierarchy of restriction operators to coarse grid problems using the submatrix of
443: a single component with either `PCHYPRE` or `PCGAMG`. The same restriction operators are then used for each of the components of the PDE within the `PCMG`
444: multigrid preconditioner. This results in a much more efficient to build and apply preconditioner than using `PCGAMG` on the entire system {cite}`kong2020highly`.
446: Options Database Keys:
447: + -pc_hmg_reuse_interpolation <true | false> - Whether or not to reuse the interpolations for new matrix values or rebuild the interpolation. This can save compute time.
448: . -pc_hmg_use_subspace_coarsening <true | false> - Whether or not to use subspace coarsening (that is, coarsen a submatrix, or coarsen on the full matrix).
449: . -hmg_inner_pc_type <hypre, gamg, ...> - What method to use to generate the hierarchy of restriction operators
450: - -pc_hmg_use_matmaij <true | false> - Whether or not to use `MATMAIJ` for multicomponent problems for saving memory
452: Level: intermediate
454: Note:
455: `MatSetBlockSize()` must be called on the linear system matrix to set the number of components of the PDE.
457: .seealso: [](ch_ksp), `PCCreate()`, `PCSetType()`, `PCType`, `PC`, `PCMG`, `PCHYPRE`, `PCHMG`, `PCGetCoarseOperators()`, `PCGetInterpolations()`,
458: `PCHMGSetReuseInterpolation()`, `PCHMGSetUseSubspaceCoarsening()`, `PCHMGSetInnerPCType()`, `PCGAMG`
459: M*/
460: PETSC_EXTERN PetscErrorCode PCCreate_HMG(PC pc)
461: {
462: PC_HMG *hmg;
463: PC_MG *mg;
465: PetscFunctionBegin;
466: /* if type was previously mg; must manually destroy it because call to PCSetType(pc,PCMG) will not destroy it */
467: PetscTryTypeMethod(pc, destroy);
468: pc->data = NULL;
469: PetscCall(PetscFree(((PetscObject)pc)->type_name));
471: PetscCall(PCSetType(pc, PCMG));
472: PetscCall(PetscObjectChangeTypeName((PetscObject)pc, PCHMG));
473: PetscCall(PetscNew(&hmg));
475: mg = (PC_MG *)pc->data;
476: mg->innerctx = hmg;
477: hmg->reuseinterp = PETSC_FALSE;
478: hmg->subcoarsening = PETSC_FALSE;
479: hmg->usematmaij = PETSC_TRUE;
480: hmg->component = 0;
481: hmg->innerpc = NULL;
483: pc->ops->setfromoptions = PCSetFromOptions_HMG;
484: pc->ops->view = PCView_HMG;
485: pc->ops->destroy = PCDestroy_HMG;
486: pc->ops->setup = PCSetUp_HMG;
488: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetReuseInterpolation_C", PCHMGSetReuseInterpolation_HMG));
489: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetUseSubspaceCoarsening_C", PCHMGSetUseSubspaceCoarsening_HMG));
490: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetInnerPCType_C", PCHMGSetInnerPCType_HMG));
491: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGSetCoarseningComponent_C", PCHMGSetCoarseningComponent_HMG));
492: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCHMGUseMatMAIJ_C", PCHMGUseMatMAIJ_HMG));
493: PetscFunctionReturn(PETSC_SUCCESS);
494: }